The invention refers to an apparatus for reprocessing thermoplastic synthetic plastic material, comprising a receptacle for the synthetic plastic material to be processed, which receptacle has a device with at least one rotating tool which conveys the synthetic plastic material through a discharge opening of the receptacle such that a component of stuffing force is exerted on the synthetic plastic material in the axial direction of this discharge opening and transmitted thereto always by the synthetic plastic material subsequently being pressed in, which discharge opening leads to an inlet opening for the synthetic plastic material arranged in the side wall of the screw housing, whereby the interior surface of the housing of the screw in the area of the inlet opening has a pocket-like enlargement which provides an additional space to accomodate synthetic plastic material and which is bound by an adjustable wall piece on that edge of the inlet opening on which the direction of rotation of the screw is directed towards the receptacle, which wall piece allows the enlargement to be at least partially closed off from the receptacle.
A device of this kind is the subject matter of an older, not previously published construction by the present applicants. This construction has the advantage that even synthetic plastic materials possessing different properties can be reliably engaged by the screw since the stuffing action of the rotating tool continuously ensures that sufficient synthetic plastic material is pressed from the side between the individual flights of the screw rotating around its longitudinal axis. Although this in itself poses the risk that the conveying efficiency of the screw becomes too great and causes overloading of the screw drive, this risk can be avoided by drawing back the adjustable wall piece in relation to the screw such that part of the synthetic plastic material engaged by the screw is returned to the receptacle. In this way it is possible to adjust the conveying efficiency of the screw to the prevailing conditions.